A Biorad MRC100 laser scanning confocal microscope with Silicon Graphics IRIS Indigo workstation and selected peripherals are requested by a group of biomedical researchers at the Medical University of South Carolina. This instrument would bring new and powerful light microscopy and computer imaging technology directly to bear upon 10 active or pending NIH projects; no other such facilities exist within the Charleston scientific community, comprising some 120 NIH projects. Immediate applications of this instrumentation include high resolution colocalization of intracellular cytoskeletal or signalling molecules in several experimental cell culture or organ systems and delineation of the spatial distribution of extracellular matrix, adhesion molecules and other differentiation markers during development or in diseases tissues. Direct experience and pilot studies suggest novel applications in counting discrete immunolocalized features such as gap junctions or parasitic antigens over large volumes of tissue and three-dimensional representation of myocardial fiber geometry in dense tissue preparations. Available expertise in confocal microscopy and in conventional light microscopy and image processing among the major users assure full utilization of both the laser scanning confocal microscope and the imaging workstation. Reliable operation of the proposed facility and access to an active community of researchers in the future are assured by past and present collaborations among major users and a specific organizational plan including technical and central administrative support.